DESCRIPTION (from the investigator's abstract): The vitreous compartment of owl monkey (Aotus trivirgatus) is currently used to evaluate viscoelastic hyaluronan (HA) ophthalmic devices before they are used in ophthalmic surgery. It is important that the HA used in these procedures be purified and noninflammatory; only the monkey vitreous test (MVT) has been able to predict with the required consistency the inflammatory nature of HA materials. It would be advantageous to have a reliable alternative method in order to reduce the frequency of primate use and to increase the availability of test alternatives. The mouse chemotaxis assay was developed as a substitute for the monkey vitreous test. Phase I testing demonstrated that the assay could be used to distinguish inflammatory HA from noninflammatory HA based on and correlated with MVT test results. The Phase II proposal will: 1) investigate additional practical modifications to the assay procedure which will increase the use and flexibility of the assay; 2) test an additional 50 to 75 samples of HA with known MVT results in order to validate the method; 3) investigate the mechanism of response via analysis of HA materials, analysis of the cell response, evaluation of peritoneal fluid, and histological evaluation of the cavity lining; and 4) continue development of a total in vitro assay which will identify inflammatory/noninflammatory HA.